I currently have Gentoo fully running on the parallella and everything runs ok.

The basic steps that I took to get it running:

Use the normal kernel images (eventually I changed some settings and recompiled it)

Download de armv7a-hardfloat stage3 tarball from one of the servers.

Copy that to the partition on my sdcard where ubuntu was on

Set up fstab

Setting up a crosscompiler on my main pc (used for distcc and recompiling the kernel with extra features)

VIDEO_CARDS="fbdev" in make.conf (needed for xorg to work)

Update and install lots of applications, which it is still working on.

ACCEPT_KEYWORDS="arm ~arm" in make.conf (To get testing versions of applications, since almost nothing has been tested enough on arm to be marked as stable by gentoo)

If you want to try do this yourself you should read the wiki for the Raspberry Pi and forum posts for that one as well. Since most of the problems you'll run into are covered there as well.

I had quite some trouble with crosscompiling, distcc seems to work however. I did however find out that my class 10 microsd is quite slow and I'll try to run my system (except the kernel) of a harddisk in a couple of days. It is especially slow when trying to compile and install programs since that involves reading and writing of lots of small files, which it is not very good at.

As for the kernel config changes, I think I'll push some of them back to the official git repo. Since one was needed to get my usb hub to recognize more than one device, which seems like a feature that would be nice in the default kernel.

So, how does it perform? Do you see 64 cores in /proc/cpuinfo? Do you get a huge 64x speedup when compiling world with 64 jobs?_________________BTC: 18wdrw8sLtruvdwr5kB3RxbbxzjDeXUpRh
LTC: LYynwaSeBLb4gHaMnkB7NQ27H6wF3Fjyxo

Bump!
A few months have elapsed, perhaps you could tell us something more about your experience with that tiny board? What performance does it have? Is it close to that "supercomputing for everybody"?
When I read description I had an impression all the buzz was about it's huge co-processor, which made me think it's much closer to GPU-style computing than to multicore PI. I would like to know how good it actually is. I wonder if there is any way to use it's power for general purpose stuff. Say, that emerge with 64 threads would be a nice indicator

Emerge with -j64 isn't going to be anywhere near 64 times as fast as single-core; 4-5x maybe, being generous. RAM contention will be the bottleneck for just about any workload that doesn't micro-manage its cache lines efficiently._________________*.ebuild // /etc/service/*

While you're probably right about that RAM being a bottleneck during compilation it still doesn't say much about it's capabilities.
AFAIR there are 2 ARM cores on one die + 64 coprocessor cores on the other die. This makes me think emerge -j 2 is where it hits the roof, yet authors seemd to claim it should do fine as a web server. Web servers are not too much into numbers crunching.
So what actually it's capabilities are? What kind of stuff can run in parallel on this board?

How does the 64 core co-processor show up under /proc/cpuinfo? Can I run an arbitrary application and have it actually use the extra hardware?

If I run 64 "hello world" programs that also simply count to 2^48, will linux schedule them on each of the 64 co-processors?_________________BTC: 18wdrw8sLtruvdwr5kB3RxbbxzjDeXUpRh
LTC: LYynwaSeBLb4gHaMnkB7NQ27H6wF3Fjyxo